U.S. patent application number 10/677917 was filed with the patent office on 2004-06-17 for drill string shutoff valve.
Invention is credited to Chan, Kwong-Onn C., He, Xiaoping, Movaffagh, Behrooz.
Application Number | 20040112644 10/677917 |
Document ID | / |
Family ID | 46204980 |
Filed Date | 2004-06-17 |
United States Patent
Application |
20040112644 |
Kind Code |
A1 |
Chan, Kwong-Onn C. ; et
al. |
June 17, 2004 |
Drill string shutoff valve
Abstract
A valve assembly connects into a drill string for opening and
closing at least one inner passage within the drill string of the
drill string. The valve assembly includes an annular valve assembly
carried in an annular passage that moves between the open and
closed positions in response to downward fluid pressure from the
surface through the annular passage. The valve assembly also
includes an inner valve assembly carried in an inner passage of the
drill string. The inner valve assembly is a two-way valve that is
actuated between open and closed positions by pressure pulses from
the surface through the inner passage. The valve assembly can be
used within coiled tubing.
Inventors: |
Chan, Kwong-Onn C.;
(Edmonton, CA) ; Movaffagh, Behrooz; (Edmonton,
CA) ; He, Xiaoping; (Edmonton, CA) |
Correspondence
Address: |
BRACEWELL & PATTERSON, L.L.P.
Attention: James E. Bradley
P. O. Box 61389
Houston
TX
77208-1389
US
|
Family ID: |
46204980 |
Appl. No.: |
10/677917 |
Filed: |
October 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10677917 |
Oct 2, 2003 |
|
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10321087 |
Dec 17, 2002 |
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Current U.S.
Class: |
175/57 ; 175/317;
175/324 |
Current CPC
Class: |
E21B 34/12 20130101;
E21B 17/18 20130101; E21B 17/07 20130101; E21B 23/004 20130101 |
Class at
Publication: |
175/057 ;
175/317; 175/324 |
International
Class: |
E21B 021/00 |
Claims
That claimed is:
1. An apparatus for opening and closing a passage of a drill
string, comprising: a concentric string of conduit for suspending a
drill bit and a motor, the concentric string of conduit defining an
inner passage and an annular passage; and an annular valve assembly
carried in the annular passage that is selectively actuated between
open and closed positions for regulating fluid flow through the
annular passage.
2. The apparatus according to claim 1, wherein the annular valve
member further comprises: an annular valve passage; and an annular
valve piston that selectively engages the annular valve passage for
opening and closing the annular valve.
3. The apparatus according to claim 2, wherein the annular valve
assembly further comprises an annular valve spring for biasing the
annular valve piston into engage with the annular valve
passage.
4. The apparatus according to claim 1, wherein the portion of the
annular passage above the annular valve assembly is in fluid
communication with the inner passage when the annular valve
assembly is open.
5. The apparatus according to claim 1, wherein the annular valve
assembly blocks fluid communication between the inner passage and
the portion of the annular passage above the annular valve assembly
when the annular valve assembly is closed.
6. The apparatus according to claim 1, wherein the annular valve
assembly is a one-way valve for allowing fluid flow axially
downward through the annular passage.
7. The apparatus according to claim 1, further comprising an inner
valve assembly carried in the inner passage that is selectively
actuated between open and closed positions for regulating fluid
flow through the inner passage.
8. The apparatus according to claim 7, wherein the inner valve
assembly is a two-way valve for allowing fluid flow through the
inner passage while the inner valve assembly is open.
9. The apparatus according to claim 7, wherein the inner valve
assembly further comprises an upward facing piston that receives
pressure pulses for actuating the inner valve between open and
closed positions.
10. The apparatus according to claim 7, wherein the inner valve
assembly further comprises an upper and a lower valve casing that
incrementally rotate and slide axially downward during each
pressure pulse.
11. An apparatus for opening and closing a passage of a drill
string, comprising: a concentric string of conduit for suspending a
drill bit and a motor, the concentric string of conduit defining an
inner passage and an annular passage; an annular valve assembly
carried in the annular passage that is selectively actuated between
open and closed positions for regulating fluid flow through the
annular passage; and an inner valve assembly carried in the inner
passage that is selectively actuated between open and closed
positions for regulating fluid flow through the inner passage.
12. The apparatus according to claim 11, wherein the annular valve
member further comprises an annular valve piston for selectively
opening and closing the annular valve assembly.
13. The apparatus according to claim 12, wherein the annular valve
assembly further comprises an annular valve spring that engages and
biases the annular valve piston to a closed position of the annular
valve assembly, the annular valve spring is contracted when the
annular valve assembly is in its open position.
14. The apparatus according to claim 11, wherein the inner valve
assembly blocks fluid communication between the portion of the
inner passage above the inner valve assembly and the portion of the
annular passage above the annular valve assembly when the inner
valve assembly is closed.
15. The apparatus according to claim 11, wherein the inner valve
assembly further comprises an upward facing piston that receives
pressure pulses for actuating the inner valve between open and
closed positions; and an upper valve casing and a lower valve
casing that incrementally rotate and slide axially downward during
each pressure pulse.
16. The apparatus according to claim 15, wherein the inner valve
assembly further comprises a plurality of vanes formed on the
interior surface of the inner passage, the lower ends of the vanes
engage the an upper portion of the lower valve casing at
preselected increments for holding the inner valve in an open
position.
17. The apparatus according to claim 16, further comprising: an
inner valve piston connected to the lower valve casing that
sealingly closes the inner valve when in an upward position, the
lower valve casing holding the inner valve piston in a downward
position while the vanes engage upper portion of the lower valve
casing.
18. The apparatus according to claim 17, wherein the upper portion
of the lower valve casing slides axially upward beyond the lower
ends of the vanes at preselected increments for closing the inner
valve assembly.
19. An method for opening and closing a passage of a drill string
suspending a drill bit and a motor, comprising: providing a
concentric string of conduit having an inner passage and an annular
passage, and an annular valve carried in the annular passage;
opening the annular valve by supplying fluid pressure in the
annular passage above the annular valve; and closing the annular
valve by discontinuing the supply of fluid pressure in the annular
passage above the annular valve.
20. The method according to claim 19, further comprising: providing
an inner valve assembly carried in the inner passage; and opening
the inner valve assembly with a pressure pulse from the surface
that causes the inner valve assembly to rotate into an open
position; and closing the inner valve assembly with another
pressure pulse from the surface that causes the inner valve
assembly to rotate into a closed position.
Description
RELATED APPLICATIONS
[0001] This continuation-in-part patent application claims the
benefit of co-pending, non-provisional patent application U.S. Ser.
No. 10/321,087, filed on Dec. 17, 2002, which is hereby
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates in general to safety shutoff valves,
and particularly to a safety shutoff valve located in a drill
string for drilling a well.
[0004] 2. Background of the Invention
[0005] Most oil and gas wells are drilled with a rotary drilling
rig. Typically, the drill string has a drill bit on the end and is
rotated to cause the drill bit to advance into the earth. A
drilling fluid is pumped down the interior passage of the drill
pipe, which exits nozzles on the drill bit and flows back up an
annular space surrounding the drill pipe along with cuttings.
[0006] Normally, the drilling fluid is a liquid called mud, which
has a weight selected to provide a hydrostatic pressure greater
than the expected earth formation pressures. When tripping the
drill string in and out of the hole, the drilling mud in the hole
and within the interior of the drill pipe provide sufficient
hydrostatic pressure to prevent a blowout. However, heavy drilling
mud can damage certain earth formations, reducing their abilities
to produce fluids after completion. For example, methane is located
in certain fairly deep coal beds. The coal formations may be
damaged by encroaching drilling mud.
[0007] Drilling with gaseous fluids, such as air, has also been
done with oil and gas wells. In one of these techniques, compressed
air flows down the interior of the drill pipe, exits the drill bit
and flows back up the annulus. A stripper seal surrounds the drill
pipe at the surface for sealing the gas pressure in the well. Also,
compressed air is used as a drilling fluid for drilling shallow
mining blast holes. Mining drilling rigs may employ a dual passage
string of drill pipe, with one of the passages being an inner
passage and the other an annular passage. A gaseous fluid such as
air is pumped down the annular passage and flows back up the inner
passage along with cuttings. The dual passage drill pipe can be
rotated to rotate the drill bit. Alternately, a downhole motor can
be utilized which may also create a reciprocating a hammer motion
as well as rotating the drill bit while the drill pipe remains
stationary.
[0008] The possibility of a blowout due to excessive earth
formation pressure is not a factor with shallow drilling of mining
blast holes. With deep oil and gas drilling, however, it must be
considered both while drilling and while tripping the drill pipe in
and out of the hole. Blowout preventers and rams are utilized to
seal around the annulus of drill pipe. The use of check valves in
the drill string has been proposed in the past. The primary barrier
to a blowout, however, continues to be the use of drilling mud with
sufficient weight to provide a higher hydrostatic pressure than any
expected pressure of the earth formations.
SUMMARY OF THE INVENTION
[0009] In this invention, a valve assembly is mounted in a string
of drill pipe for selectively closing the passages of the drill
pipe. The valve assembly includes an annular valve assembly carried
in an annular passage. The annular valve assembly selectively
actuates between open and closed positions due to fluid pressure
above the annular valve assembly. When the fluid pressure in the
annular passage above the annular valve assembly is less than a
predetermined amount, the annular valve assembly closes. The
annular valve assembly opens when the pressure in the annular
passage above annular valve assembly increases above the
predetermined amount.
[0010] The string of drill pipe also includes an inner passage
extending axially through the drill pipe. The valve assembly
includes an inner valve assembly carried in the inner passage. The
inner valve assembly includes a pair of valve members that rotate
upon receiving pressure pulses from the surface. The pressure
pulses cause the valve members of the inner valve assembly to
rotate, which actuates the inner valve assembly between open and
closed positions. Fluid can flow axially upward or downward through
the inner valve assembly while in its open position.
[0011] The valve assembly of this embodiment is particularly for
use with a drill string for drilling with a gaseous drilling fluid.
The drill string is preferably of a dual passage type, having an
inner conduit and an annular passage surrounding the inner conduit.
The valve assembly is particularly useful for drill strings that
are coiled tubing. Because coiled tubing cannot be rotated, the
inner and outer valve assemblies are actuated by pressure from the
surface rather than rotating the drill string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A and 1B comprise a vertical sectional view of a
valve assembly constructed in accordance with this invention and
shown in an open position.
[0013] FIGS. 2A and 2B comprise a vertical sectional view of the
valve assembly of FIGS. 1A and 1B, but shown in a closed
position.
[0014] FIG. 3 is a perspective view of part of a lower sub of the
outer member of the valve assembly of FIGS. 1A and 1B.
[0015] FIG. 4 is a side elevational view, partially sectioned, of
the lower sub of FIG. 3.
[0016] FIG. 5 is a sectional view of the lower sub of FIG. 3, taken
along the line 5-5 of FIG. 4.
[0017] FIG. 6 is a sectional view of the lower sub of FIG. 3, taken
along the line of 6-6 of FIG. 4.
[0018] FIG. 7A comprises a vertical sectional view of an
alternative valve assembly constructed in accordance with this
invention and shown in an open position.
[0019] FIG. 7B is a vertical sectional view of the valve assembly
of FIG. 7A in a closed position.
[0020] FIG. 8 is an exploded view of a portion of the valve
assembly shown in FIG. 7A.
[0021] FIG. 9 is a vertical sectional view of the valve assembly of
FIG. 7A showing the flow of circulation when the valve assembly has
its inner and annular valves open.
[0022] FIG. 10 is a vertical sectional view of the valve assembly
of FIG. 7A showing the flow of circulation when the annular valves
are open and the inner valve is closed.
[0023] FIG. 11 is a vertical sectional view of the valve assembly
of FIG. 7A showing a flow of circulation when the annular valves
are closed and the inner valve is open.
[0024] FIG. 12 is a vertical sectional view of the valve assembly
showing another flow of circulation when the annular valves are
closed and the inner valve is open.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring to FIG. 1, valve assembly 11 includes an outer
tubular member 13, which is made up of several components. An upper
adapter 15 forms the upper end of outer member 13. Upper adapter 15
is a tubular member having threads on its upper end for connection
to an outer conduit 17 of a dual passage drill string 19. Drill
string 19 preferably has an inner conduit 21 extending through it.
An annular passage 23 surrounds inner conduit 21, and an inner
passage 25 extends through inner conduit 21. Inner conduit 21 and
outer conduit 17 may be made of continuous coiled tubing, which is
typically of metal. Alternately, outer conduit 17 may be made up of
segments of pipe secured together, and inner conduit 21 could be
formed of sections of pipe that stab together.
[0026] Outer member 13 also has an upper sub 27 that secures to the
lower end of adapter 15. Upper sub 27 is a tubular member that has
a plurality of pins 29 secured to it. Preferably there are two sets
of pins 29, each pin 29 in each set being axially aligned with the
others in the same set. The sets of pins 29 are spaced 180.degree.
apart and extend radially inward. Upper sub 27 also has a plurality
of spaced apart downward facing lugs 31 on its lower end. Lugs 31
contact an upper shoulder of a lower sub 33 of outer member 13 when
valve assembly 11 is in the retracted position shown in FIGS. 1A
and 1B.
[0027] Lower sub 33 is a tubular member that has an upper reduced
diameter portion that inserts into upper sub 27 and contains a pair
of slots 35 for engagement by pins 29. Slots 35 are spaced
180.degree. from each other in this embodiment. As shown in FIG. 3,
each slot 35 has a plurality of transverse portions 37 that extend
circumferentially about 90.degree. and are parallel to each other.
Each transverse portion 37 is perpendicular to the longitudinal
axis of lower sub 33 and leads to an axial portion 39 that extends
along the length of lower sub 33. Each slot 35 does not extend
entirely through the sidewall of lower sub 33, thus does not
communicate with the interior of the lower sub 33. Lower sub 33
also has a plurality upward facing lugs 41 that have spaces between
them for receiving downward facing lugs 31 (FIG. 1B) of upper sub
27.
[0028] There are more transverse portions 37 of each slot 35 than
pins 29. Each set has three pins 29 in this example, while there
are four transverse portions 37 (FIG. 3) in each slot 35. Pins 29
are located in the lower three transverse slots 37 while valve
assembly 11 is in the open and retracted position of FIGS. 1A and
1B. While in this position, lugs 31 and 41 are intermeshed with
each other as shown in FIG. 1B. Each space between each upward
extending lug 41 is wider than each downward extending lug 31. This
allows upper sub 27 to rotate counterclockwise (looking downward)
an increment relative to lower sub 33 while lugs 41 and 31 are
intermeshed. While doing so, pins 29 will move from the transverse
portions 37 to the axial portion 39. Then, upper sub 27 can move
upward relative to lower sub 33 a short distance until the
uppermost pin 29 of each set (FIG. 1B) contacts the upper end of
axial portion 39. At this point, upper sub 27 can be rotated an
increment clockwise relative to lower sub 33 to cause the three
pins 29 to enter the upper three transverse portions 37.
[0029] The total number of transverse portions 37 should exceed the
total number of pins 29, however the number could differ from the
four transverse portions 37 and three pins 29 shown in the
preferred embodiment. Although lugs 31, 41 allow limited rotation
of upper sub 27 relative to lower sub 33, they will transmit torque
once in engagement with each other.
[0030] Referring again to FIG. 1B, a lower adapter 43 secures by
threads to the lower end of lower sub 33. Lower adapter 43 has the
same configuration as upper adapter 15 for connecting to another
portion of drill string 19. Preferably lower adapter 43 connects
into drill string 19 at a fairly close distance to a drill motor
and bit assembly (not shown). Outer member 13 thus is made up of
upper adapter 15, upper sub 27, lower sub 33 and lower adapter 43.
The upper portion of outer member 13, which is made up of upper sub
27 and upper adapter 15, will telescope upward relative to the
lower portion, which is made up of lower sub 33 and lower adapter
43. FIGS. 1A and 1B show the retracted position, while FIGS. 2A and
2B show the extended position.
[0031] An inner member 45 extends through outer member 13. Inner
member 45 has a number of components, and its outer diameters are
all less than the inner diameters of adjacent portions of outer
member 13, resulting in an annular passage 47 between inner member
45 and outer member 13. Inner member 45 has a tubular upper portion
49 that joins inner conduit 21 of drill string 19. Inner upper
portion 49 has outward extending lugs 50 that are received within a
recess of upper sub 27. The recess is defined by an upward facing
shoulder 52 of upper sub 27 and the lower end of upper adapter 15.
Lugs 50 are spaced apart circumferentially from each other so as to
not impede fluid flow through annulus 47. Lugs 50 and shoulder 52
prevent any axial movement of inner upper portion 49 relative to
upper sub 27.
[0032] Inner upper portion 49 has a valve member 51 formed on its
lower end. Valve member 51 comprises a tube that has a closed lower
end 53. A plurality of ports 55 are located in the sidewall of
valve member 51 directly above closed end 53. Valve member 51 lands
within a valve sleeve 57, which has an upward facing conical
shoulder 59 that provides a lower limit for the downward travel of
valve member 51. Valve sleeve 57 sealingly receives closed end 53.
A plurality of bypass ports 63 are located in valve sleeve 57, with
each port 63 registering with one of the ports 55 when in the open
position of FIGS. 1A and 1B.
[0033] An inner member lower tube 65 is secured to valve sleeve 57.
The inner diameter of lower tube 65 is greater than the outer
diameter of valve sleeve 57 at ports 63 by a selected amount to
create an annular clearance 66. While in the position shown in FIG.
1B, fluid may flow upward, as indicated by the arrows, through
clearance 66, ports 63, 55, and into the interior of valve member
51. Ports 63 and clearance 66 serve as a bypass to allow flow
around closed end 53 of valve member 51 while in the open
position.
[0034] Lower tube 65 is axially retained with a lower portion of
outer member 13, which comprises lower sub 33 and lower adapter 43.
This is handled by a plurality of lugs 67 on the exterior of lower
tube 65. Lugs 67 locate within a recess that is formed by a
downward facing shoulder 69 of lower sub 33 and the upper end of
lower adapter 43. Lugs 67 are spaced apart circumferentially to
allow fluid flow through annular passage 47.
[0035] An inner passage 71 extends through the various components
of inner member 45. Inner member 45, like outer member 13, has an
upper portion that moves axially relative to a lower portion. The
upper portion is made up of inner upper portion 49 and valve member
51. The lower portion of inner member 45 is made up of valve sleeve
57 and lower tube 65.
[0036] In operation, valve assembly 11 is connected into drill
string 19 at a point near the lower end of the drill string.
Typically, the operator would place valve assembly 11 in a closed
position prior to running drill string 19 into the well. This may
be done at the drill rig floor by restraining lower adapter 43
against rotation while rotating outer adapter 13 about one-fourth
turn in a counterclockwise direction looking downward. This causes
pins 29 (FIG. 1B) to move from transverse portions 37 to axial
portion 39 (FIG. 3). Either before or after the incremental
rotation, the operator suspends valve assembly 11 vertically. This
causes upper sub 27 and its pins 29 to move upward relative to
lower sub 33 and its slot 35 (FIG. 3). When the upper pins 29 reach
the upper ends of axial slots 39, the operator rotates upper
adapter 15 one-fourth turn back clockwise relative to lower adapter
43. Pins 39 are now in the upper three transverse slot portions 37
(FIG. 3). Pins 39 and transverse slot portions 37 of slot 35 thus
serve as a retainer to maintains valve assembly 11 in the extended
position.
[0037] As upper sub 27 moves upward relative to lower sub 33, valve
member 51 also moves upward relative to valve sleeve 57. Closed
lower end 53 moves upward to the position of FIG. 2B above ports 63
in valve sleeve 57. Any upward flow through inner passage 71 will
be blocked by closed end 53.
[0038] When the drill bit reaches the bottom of the well, the
operator will open valve assembly 11 by rotating drill string 19
one-fourth turn counterclockwise. Because of the weight of drill
string 19 on valve assembly 11, the lower portion of outer member
13, including lower sub 33, does not rotate, thus causing each set
of pins 39 to now enter axial portion 39 of slot 35 (FIG. 3). The
operator allows the weight of the drill string above valve assembly
11 to move the upper portion of outer member 13 downward relative
to the lower portion of outer member 13 until lugs 31 contact the
shoulders between lugs 41. Outer member 13 will then be in
compression. At this point, pins 29 (FIG. 1B) will be in alignment
with the three lower transverse portions 37 (FIG. 3). The operator
rotates drill string 19 one-fourth turn clockwise, causing upper
sub 27 to rotate relative to lower sub 33, placing pins 29 at the
ends of the transverse portions 37. At the same time the upper
portion of outer member 13 moved downward, valve member 51 also
moved downward in valve sleeve 57 to the position shown in FIG. 1B.
Ports 63 and 55 will now align with each other, placing valve
assembly 11 in an open position.
[0039] The operator pumps a fluid down annular passage 23, the
fluid typically being a gas such as air. The fluid flows down
annular passage 47 and is used to drive the drill motor to rotate
the drill bit (not shown) while drill string 19 remains stationary.
Cuttings and return air flow up inner passage 71, through clearance
66 and ports 63 and 55 into the interior of valve member 51. The
fluid continues to flow up inner passage 71 into inner passage 25
of drill string 19. When the operator wishes to close valve
assembly 11, he simply reverses the steps mentioned above.
Normally, when tripping the drill string 19 out of the well such as
to change the drill bit, the operator will close the valve
assembly.
[0040] The invention has significant advantages. The valve assembly
provides a safety shutoff to prevent the flow of gas or other
formation fluids up through the drill string, particularly while
running the drill string into the well or retrieving the drill
string from the well. The valve assembly is particularly useful
when drilling into deep coal beds that contain methane gas. The use
of air as a drilling medium avoids having to utilize liquid
drilling fluids, which tend to encroach into and damage such
formations. The valve is easily moved between open and closed
positions by manipulating the drill string. The valve can be
retained in either the open or closed position.
[0041] Referring to FIGS. 7A and 7B, an alternative embodiment of
valve assembly 211 is shown for a dual passage conduit 217. Conduit
217 supporting valve assembly 211 is preferrably a string of coiled
tubing. Coiled tubing 217 is unable to be rotated, compressed, and
extended during drilling operations like the assembly shown in
FIGS. 1A-6, therefore a manner of regulating fluid flow within the
conduit from the drill bit is desired.
[0042] Valve assembly 211 preferably includes an outer tubular
member 213 and an inner tubular member 215. Valve assembly 211 is
located within a lower portion of coiled tubing 217 extending from
the surface. In the preferred embodiment, outer tubular member 213
is a portion of coiled tubing 217, and inner tubular member 215
within outer member 213 is also a portion of coiled tubing 217.
Alternatively, inner and outer tubular members 213, 215 of valve
assembly 211 can be fixedly attached to a dual passage string of
coiled tubing 217. Valve assembly 211 supports a downhole motor 219
and a drill bit 221 below valve assembly 211. Downhole motor 219 is
preferably a centrifugal motor that is powered, in a manner known
by those in the art, by fluid transmitted through coiled tubing
217. Motor 219 drives drill bit 221 during drilling operations.
[0043] The inner surface of outer tubular member 213 and the outer
surface of inner tubular member 215 define an outer annulus 223 for
fluid flow through an outer passage of coiled tubing 217 to drill
bit 221. The interior surface of inner tubular member 215 defines
an inner passage 225 in fluid communication with the inner passage
of coiled tubing 217 and drill bit 221. Drill bit 221 is in fluid
communication with inner and outer passages 223, 225 through motor
219.
[0044] Valve assembly 211 preferably includes an annular valve
assembly 227 located in outer annulus 223 between outer and inner
tubular members 213, 215. Preferably, a valve seat 229 extends
radially outward from the outer surface of inner tubular member 215
and sealingly engages the interior surface of outer tubular member
213. A valve passage 231 extends axially through valve seat 229.
Preferably, there are a plurality of valve passages 231 extending
axially through valve seat 229 around the circumference of inner
tubular member 215. Annular valve passages 231 thereby provides a
plurality of passages 231 for fluid to flow through outer annulus
223 between portions of outer annulus 223 above and below valve
seat 229.
[0045] A valve piston 233 regulates flow through valve passages
231. Valve piston 233 preferably has a circular cross section
allowing it to slidingly engage the outer surface of inner tubular
member 215. Valve piston 233 selectively actuates between open and
closed positions within valve assembly 227 to regulate flow through
valve passages 231 by engaging and disengaging valve seat 229. A
valve spring 235 located axially below valve piston 233 biases
valve piston 233 toward valve seat 229 and valve passages 231. A
spring retainer 237, located below valve spring 235, provides a
physical barrier for spring 235 to engage while biasing valve
piston 233 toward valve seat 229.
[0046] A predetermined fluid pressure within outer annulus 223
above valve passage 231 to compress valve spring 235 and disengages
valve piston 233 from valve seat 229, thereby opening annular valve
assembly 227. Preferably, when fluid pressure in the portion of
outer annulus 223 is less than the predetermined amount above valve
seat 229, valve spring 235 expands against valve piston 233 until
valve seat 229 and valve piston 233 are in substantial contact with
each other. Therefore, annular valve assembly 227 actuates between
open and closed positions through pressure supplied from the
surface through outer annulus 223. When pressure is not supplied
through outer annulus 223 toward valve assembly 211, annular valve
assembly 227 is in its closed position as shown in FIG. 7B. When
pressure is supplied through outer annulus 223 toward valve
assembly 211 annular valve assembly 227 is in its open position as
shown in FIG. 8A.
[0047] Valve assembly 211 also includes an inner valve assembly 241
located within in inner tubular member 215. Inner valve assembly
241 preferably includes an upper valve member 243 having an upper
valve member casing 245, which slides within the interior of inner
tubular member 215. An upper valve member piston 247 is located
along a central axis within upper valve member casing 245. An upper
valve member spider 249 connects a lower portion of upper valve
member piston 247 to an interior surface of upper valve member
casing 245. Upper valve member piston engages upper valve member
casing 245 through upper valve member spider 247 to actuate upper
valve member 243 up and down within inner tubular member 215.
Preferably, upper valve member piston 247 is selectively actuated
through pressure pulses acting on an enlarged upper surface of
upper valve member piston 247 from the surface through inner
tubular member 215.
[0048] A lower valve member 251, located below upper valve member
243 preferably includes a lower valve member casing 253 which
slides within inner tubular member 215. An upper surface of lower
valve member casing 253 engages a lower surface of upper valve
member casing 245 as upper valve member 243 actuates up and down
due to the pressure pulses experienced by upper valve member piston
247. Lower valve member 251 also preferably includes a lower valve
member spider 255 extending between interior surfaces of lower
valve member casing 253. Lower valve member casing 253 preferably
includes an inner valve piston 259 that is connected to lower valve
member spider 255 and extends axially downward through inner
tubular member 215 and lower valve member 251.
[0049] An inner valve seat 257 is formed within inner tubular
member 215 below lower valve member casing 253 and above a portion
of inner valve piston 259. Preferably, inner valve seat 257 is
formed with a circular cross section having a smaller radius than
lower valve member casing 253. Inner valve seat 257 is fixedly
attached to inner tubular member 215, thereby remaining stationary
relative to lower valve member 251 as inner valve piston 259 moves
axially upward and downward inside inner tubular member 215. An
inner valve spring 261, located below inner valve piston 259,
biases inner valve piston 259 axially upward toward upper valve
member 243 and inner valve seat 257. Preferably, inner valve piston
259 has a portion which sealingly engages inner valve seat 257 when
inner valve piston 259 is biased upward by inner valve spring 261.
When inner valve piston 259 engages inner valve seat 257 inner
valve assembly 241 is in its open position. When inner valve spring
261 is contracted so that inner valve piston 259 is below inner
valve seat 257, inner valve assembly 241 is in its open position as
shown in FIG. 7A. An inner valve retainer 263 is preferably located
below inner valve spring 261 for providing a surface against which
inner valve spring 261 engages to thereby bias inner valve piston
259 axially upward.
[0050] Inner valve spring 261 expands and contracts upon engagement
by inner valve piston 259. Upward and downward movements of lower
valve member casing 253 move inner valve piston 259 axially upward
and downward relative to inner tubular member 215. Lower valve
member casing moves axially upward and downward relative to inner
tubular member 215 due to axial upward and downward movement of
upper valve member 243, which is actuated by pressure pulses on
upper valve member piston 247.
[0051] Referring to FIGS. 7A, 7B and 8, a plurality of guide vanes
265 are preferably formed on the interior surface of inner tubular
member 215 within inner valve assembly 241. Preferably, guide vanes
265 are formed an axial depth to engage upper valve member 243 and
the upper surface of lower valve member 251 (as shown with dotted
lines in FIGS. 7A and 7B. The lower end of each guide vane 265
preferably includes a sloping face 267. A plurality of upper keys
269 are formed on the outer surface of upper valve member casing
245. Upper keys 269 preferably slide within guide vanes 265 as
upper valve member 243 moves axially upward and downward relative
to inner tubular member 215. Upper keys 269 preferably include
sloped faces 271 located toward the axially upward portion of upper
keys 269. Sloped faces 271 preferably engage sloped downward faces
267 of guide vanes 265 as upper valve member 243 slides axially
downward relative to guide vanes 265 and inner tubular member
215.
[0052] The combination of upper sloped faces 271 of upper keys 269
and downward sloping faces 267 of guide vanes 265 causes upper
valve member 243 to rotate a predetermined incremental amount.
Preferably, there are as many upper keys 269 as there are slots
between guide vanes 265 so that an upper key 269 is always located
within a guide vane 265 as upper valve member 243 slides axially
upward and downward within guide vanes 265. After being actuated to
an axial depth, such that the engagement as sloped downward faces
267 of guide vanes 265 and upper sloped faces 271 of upper keys 269
causes upper valve member 243 to rotate incrementally, each upper
key 269 rotates into position for sliding engagement with an
adjacent guide vane 265.
[0053] Preferably, a plurality of sloped surfaces 273 of upper
valve member casing 245 are formed at the axially lower end of
upper valve member casing 245. Sloped surfaces 273 preferably
include downward facing crests 275 and upward facing valleys 277.
The combination of downward facing crests 275 and upward facing
valleys 277 form a grooved profile for engaging lower valve member
casing 253 of lower valve member 251. Upper keys 269 preferably
include lower sloped faces 279. The slopes of lower sloped faces
279 preferably correspond to sloped surfaces 273 of upper valve
member casing 245. Accordingly, downward crest 275 and upper
valleys 277 are also formed by lower sloped faces 279 of upper keys
269.
[0054] Preferably, a plurality of lower keys 281 are formed around
the outer surface of lower valve member casing 253. A sloped face
283 is formed toward the axially upper portion of lower keys 281
for engaging sloped faces 271 of upper keys 269. A flat upper face
285 is also formed at an axially upward portion of lower keys 281
for engaging upper keys 269 at downward facing crest 275.
Preferably, lower valve member casing 253 has sloped surfaces 287
formed on its upper end for engaging sloped surfaces 273 of upper
valve member 245. Sloped surfaces 287 of lower valve member 251
preferably include upward protruding crests 289 and downward facing
valleys 291. Preferably, upward facing crests 289 include a flat
portion rather than protruding to a point. Sloped face 283 of lower
keys 281 is formed along one of sloped surfaces 287 toward upward
protruding crest 289. Preferably, flat portion 285 of lower key 281
is formed to correspond with the flat upper portion of upward
protruding crest 289. Preferably, lower keys 281 are intermittently
spaced around the circumference of lower valve member casing 253 so
that the number of lower keys 281 is substantially half the number
of upper keys 269 and substantially half the number of guide vanes
265.
[0055] Sloped surface 283 engages sloped surface 279 of upper keys
so that lower valve member 251 rotates an incremental step relative
to upper valve member 243. At one incremental step of lower valve
member 251 relative to upper valve member 243, downward facing
crests 275 extend into downward facing valleys 291 while upward
facing crest 289 extend into upper facing valleys 277. While in
this position, flat portion 285 of lower keys 281 is at a position
between upper keys 269. Upon sloped surfaces 273 and 287 engaging
each other as described. Flat portion 285 of lower keys 281 engage
guide vanes 265 as lower and upper valve members 243, 251 slide
axially upward through inner tubular member 215 when flat portion
285 is located between upper keys 269. Flat portion 285 of lower
keys 281 prevent lower valve member 251 from sliding axially upward
beyond sloped downward faces 267 of guide vanes 265.
[0056] Upon receiving another pressure pulse, upper valve member
243 slides axially downward relative to guide vanes 265 within
inner tubular member 215. Sloped surfaces 273 of upper valve member
243 engage sloped surfaces 287 of lower valve member 251 which is
being held in place against sloped downward faces 267 of guide
vanes 265 by inner valve spring 261. As upper valve member 243
continues to engage lower valve member 251, upper valve member 243
and lower valve member 251 slide axially downward relative to guide
vanes 265 so that flat portion 285 of lower keys 281 are no longer
in engagement with sloped downward faces 267 of guide vanes 265.
While lower valve member 251 is being pushed axially downward by
upper valve member 243, lower sloped faces 279 of upper keys 269
engage sloped faces 283 of lower keys 281. The engagement of sloped
surfaces 283 of lower keys 281 and sloped surface 271 of upper keys
269 causes lower valve member 251 to rotate incrementally relative
to upper valve member 243. Upon incremental rotation, flat portion
285 of lower keys 281 is engaging the downward facing crest portion
of upper keys 269 which correspond to downward crests 275 of upper
valve member 243.
[0057] As upper valve member 243 and lower valve member 251
continue to move axially downward relative to guide vanes 265,
upper sloped faces 271 of upper keys 269 engage downward sloping
faces 267 of guide vanes 265, which rotates both upper valve member
243 and lower valve member 251 in incremental step relative to
guide vanes 265 and inner tubular member 215. Upon rotating this
incremental step, upper keys 269 and lower keys 281 are aligned for
sliding axially upward within guide vanes 265 (not shown). After a
pressure pulse through inner passage 275 ceases, upper valve member
243 and lower valve member 251 slide axially upward through inner
tubular member 215 within guide vanes 265. With lower keys aligned
such that flat portion 285 is engaging downward facing crest 275 of
upper keys and upper valve member 243, lower keys 281 are allowed
to slide within guide vanes 265 which allows inner valve spring 261
to push lower valve member 251 axially upward so that inner valve
piston 259 engages inner valve seat 257 as shown in FIG. 7B. Sloped
face 283 of lower keys 281 slidingly engages the point of downward
sloping faces 267 of guide vanes 269 to rotate lower valve member
casing 253 relative to upper inner valve member casing 245 another
incremental step. When rotated, as shown in FIG. 7B, flat portion
285 slides partially up lower sloped faces 279 of upper keys 269. A
gap is formed between sloped faces 279, 283 in the closed position
shown in FIG. 7B.
[0058] Upon receiving another pressure pulse through inner passage
225, inner valve member 243 engages lower valve member 251 along
guide vanes 265. Lower valve member 251 rotates axially relative to
upper valve member due to sloped surfaces 273 and 287 after sliding
axially downward below guide vanes 265. After upper valve member
243 makes another incremental rotation relative to guide vanes 265
due to slope downward face 267 and upper sloped face 271 on upper
keys 269 and guide vanes 265, flat portion 285 of lower keys 281
are positioned within upper valleys 277 between upper keys 269. In
this position, there is no gap between the grooved profiles of
upper and lower casings 245, 253. As lower valve member 251 and
inner valve member 243 begin sliding axially upward relative to
guide vanes 265 and inner tubular member 215, flat portion 285 of
lower keys 281 engages guide vanes 265 and thereby prevents lower
valve member 251 from sliding axially upward within guide vanes
265.
[0059] In operation, an operator has a variety of valve
configurations for air flow within valve assembly 211. FIGS. 9
through 12 show various configurations available to operators using
valve assembly 211 during drilling operations. Referring to FIG. 9,
inner valve assembly 241 is shown in its open position as shown in
FIG. 7A. In the configuration shown in FIG. 9, the operator
supplies air through outer annulus 223. Providing air through outer
annulus 223 opens annular valve assembly 227 thereby allowing air
flow to power motor 219 and to drill bit 221. Air being discharged
from drill bit 221 flows into inner passage of drill bit 221 or
into an annular region surrounding drill bit 221 and valve assembly
211 within the well formation. Air flowing into the inner opening
of drill bit 221 flows through the central opening of motor 219 and
into inner valve assembly 241. With the inner valve assembly in the
open position as shown in FIG. 9 air and cuttings from drill bit
221 flow through inner passage 225 to the surface.
[0060] Referring to FIG. 10, inner valve assembly 241 is actuated
towards closed position with a pressure pulse as described above.
The operator supplies air through outer annulus 223 which in turn
opens annular valve assembly 227. Air passing through annular valve
assembly 227 continues through annular passage 223 to power motor
219 which drives drill bit 221. Discharged air and drilling
cuttings cannot flow into inner passage 225 because inner valve
assembly is in its closed position. Therefore, discharged air and
drill cuttings from drill bit 221 flow up the annulus formed around
the exterior of valve assembly 211 within the well formation.
[0061] Referring to FIG. 11, an operator has an alternative option
of not supplying air through outer annulus 223. By not supplying
air through outer annulus 223, annular valve assembly 227 closes
therefore blocking flow of air and drill cuttings up outer annulus
223 towards the surface. Inner valve assembly 241 is shown in its
open position in FIG. 11. In operation, the operator pumps air down
an annular passage formed outside of valve assembly 211 and outer
tubular member 213 through the well formation. Upon reaching drill
bit 221, air and cuttings flow into inner passage 225 and through
open inner valve assembly 241 back up to the surface.
Alternatively, as shown in FIG. 12, the operator can pump air
through inner passage 225 through valve assembly 211 to motor 219
and drill bit 221. Like the configuration shown in FIG. 11, annular
valve assembly 227 in FIG. 12 is also in its closed position as
operator is not supplying air through outer annulus 223 through
annular valve assembly 227. Air flowing through inner passage 225
inner valve 211 and out of inner portion of drill bit 221 flows
into the annular chambers of the well formation surrounding valve
assembly 211 and coiled tubing 217. The discharged air and cuttings
from drill bit 221 flow up an annular portion surrounding coiled
tubing 217 within the well formation being drilled back up to the
surface.
[0062] In each of the configurations shown in FIGS. 9-12, in the
event the operator needs to shut off all fluid flow within coiled
tubing 217 from drill bit 221, the operator can close annular valve
assembly 227 by discontinuing any downward air flow through annular
passage 225 with a pulse of air pressure against upper valve member
piston 247 to cause lower valve member 251 to rotate so that inner
valve piston 259 engages inner valve seat 257 upon being pushed
axially upward with inner valve spring 261 after the pressure pulse
is completed. Valve assembly 211 provides a way for the operator to
close outer annulus 223 and inner passage 225 during drilling
operations with coiled tubing 217, which cannot be actuated like
valve assembly 11 shown in FIGS. 1A through 6. Valve assembly 211
provides an operator deciding to use dual passage coiled tubing
with a control system comparable to valve assembly 11 shown in
FIGS. 1A through 6 which requires rotating and compressing and
retracting the dual passage drill string.
[0063] Coiled tubing 217 cannot rotate like the drill string shown
in FIGS. 1A-6. Valve assembly 211 provides a way of opening and
closing valves in inner and annular valve passages 223, 225. Valve
assembly 211 allows an operator to regulate flow through inner and
annular passages 223, 225 of coiled tubing 217 for circulation of
drill cuttings and drilling fluid during drilling operations.
Coiled tubing 217 can be preferable because it is easier to remove
for repairs than some other drill strings.
[0064] While the invention has been shown in only some of its
forms, it should be apparent to those skilled in the art that it is
not so limited but is susceptible to various changes without
departing from the scope of the invention. For example, although
the drill strings shown have dual passages within it, the valve
assembly could also operate with a single passage drill string,
with the exterior of the valve assembly serving as an annulus
passage for return flow.
* * * * *